Thermoplastic molding compositions having various properties, such as ceramic like properties, may be formed into diverse articles for use in numerous applications. In the decorative surfacing industry custom colors and special-effect appearances are desirable properties for customer acceptance.
One such decorative colorant is described in U.S. Pat. No. 5,510,398 to Clark et. al. A speckled surface is achieved through a non-dispersing pigment as opposed to a filler because the non-dispersing pigment does not appreciably add to the base color of the resin. Rather, the non-dispersing pigment provides a separate, visibly distinct and identifiable color at numerous sites across the surface of the material wherever the pigment material is visible. In other words, the speckle is visible in the filled polymer matrix as a distinct region of contrasting color. In a similar fashion, thermoset colorants are used to achieve non uniform coloring as described in U.S. Pat. No. 5,489,656.
U.S. Pat. No. 5,387,381 discloses a process for combining powder and accent color pellets to achieve wood grain effect. U.S. Pat. Nos. 5,053,176, 5,232,751 and 4,299,792 describe mechanical devices to achieve non uniform colored articles.